Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 250729
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
229 AM EST TUE NOV 25 2014

.SYNOPSIS...
ISSUED AT 401 PM EST MON NOV 24 2014

RAIN AND MILD TEMPERATURES WILL GIVE WAY TO A PERIOD OF LAKE
ENHANCED SNOW LATE THIS AFTERNOON INTO TUESDAY MORNING. COLDER
TEMPERATURES ALONG WITH ADDITIONAL CHANCES FOR SNOW WILL CONTINUE
ALL THE WAY THROUGH THE THANKSGIVING DAY HOLIDAY WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 219 AM EST TUE NOV 25 2014

...WELCOME BACK WINTER...

SYNOPTIC PATTERN AND OBSERVATIONS:

DEEP SFC LOW TRACKING NE THROUGH QUEBEC EARLY THIS MORNING...WITH A
COLD FRONT WITH SHARP CONVERGENCE EXTENDED BACK THROUGH NRN
MICHIGAN...YET SLOWLY SINKING SOUTH. THE ASSOCIATED UPPER TROUGH IS
JUST WEST OF US WITH AN EMBEDDED SHORTWAVE/VORT MAX...DEEP MOISTURE
AND DEFORMATION RIDING ALONG AND NORTH OF THE COLD FRONT. THE
RESULTANT DEEP H8-H5 FORCING/-DIVQ HOWEVER IS HEADING NORTH OF
EASTERN UPPER...BUT THE BACK EDGE OF THE SYNOPTIC SNOWS ACROSS
WISCONSIN ARE SLOW TO LIFT NE...BUT SNOW INTENSITY IS WANING. WE
ARE IN THE PERIOD OF LAKE ENHANCED SNOWFALL...AS H8 TEMPS HAVE
FALLEN SUFFICIENTLY TO REALLY GET THE LAKES GOING. THIS IS SEEN
ON LATEST RADAR IMAGERY WITH BANDED STRUCTURES EMBEDDED IN THE
SYSTEM SNOW. ROUGHLY 1-3" OF SNOW HAD FALLEN THROUGH
MIDNIGHT...FOCUSED PRIMARILY ALONG THE FRONT AND ALMOST ALL
SYNOPTIC. RIGHT NOW WE ARE IN THE GREATEST LAKE EFFECT
ENHANCEMENT...AND SNOWFALL RATES HAVE REALLY KICKED IN. 1-2"/HR
SNOWS ARE FOCUSED ALONG THE FRONT AND IN THE NW/WNW FLOW REGIMES
OF NRN LOWER (ANTRIM TO OTSEGO COUNTY). A MORE NORTHERLY
COMPONENT TO THE WIND ACROSS EASTERN UPPER...LEAVES MUCH LESS
SNOW...ALMOST ALL BY SYNOPTICS (OUTSIDE OF FAR WESTERN SECTIONS OF
CHIP/MACK). THE SYNOPTIC SNOW HAS ALL BUT LEFT THE COUNTIES NEAR
SAGINAW BAY...AND ONLY SOME VERY LIGHT SNOWS ACROSS ALPENA COUNTY.
WILL CANCEL THE ADVISORY THERE...ALTHOUGH WET ROADS COULD ICE UP
SOME BY DAYBREAK FOR A SLIPPERY COMMUTE.

SYNOPTIC PATTERN EVOLUTION AND ASSOCIATED WEATHER:

THE SFC LOW KEEPS ON TRUCKING NE WITH THE SFC FRONT SAGGING SE
THROUGH THE CWA. WE LOSE THE STRONGER LOW LEVEL CONVERGENCE WITH THE
FRONT...AND THE DEFORMATION/DEEP MOISTURE/CYCLONIC CONVERGENCE
THROUGH THE DAY. FOR THE MORNING HOWEVER...WE DO HAVE ALL OF THESE
MECHANISMS STILL IN PLAY WITH INVERSION HEIGHTS AROUND 6KFT...AND
THE LOW LEVEL 1000-850MB WIND FLOW IS FAIRLY STEADY ACROSS NRN LOWER
WITH SOME BACKING ACROSS LAKE SUPERIOR. THE DEEP DGZ MAY NOT PROVE
TO BE TOO SIGNIFICANT IN THE FLUFF FACTOR/POTENTIAL HIGHER SNOWFALL
AMOUNTS...AS THE MAX OMEGA ISN`T CO-LOCATED THERE. WINDS BACK
EVERYWHERE BY LATE DAY...INVERSION HEIGHTS FALL TO AROUND 4KFT...AND
THE SNOW REALLY WINDS DOWN...AND GETS SPREAD ACROSS ALL OF NW
LOWER...MAINLY NORTH OF M-32....AND ACROSS MAINLY CHIPPEWA COUNTY IN
EASTERN UPPER. CAN SEE AROUND 3 INCHES THIS MORNING IN THE IN AND
AROUND AN AXIS THAT RUNS THROUGH CHARLEVOIX AND OTSEGO COUNTIES WITH
MOST ALL FLOW REGIMES SEEING A HALF INCH OR LESS IN THE AFTERNOON.
MAYBE AN INCH IS POSSIBLE DOWNWIND OF LITTLE TRAVERSE BAY DUE TO
FROM ADDED FETCH AND CONVERGENT WINDS FUNNELING THROUGH THERE.

TONIGHT...WINDS CONTINUE TO BACK...OUT OF THE SSW AND TO AROUND
10KTS IN THE 1000-850MB LAYER...WITH ONLY LAKE EFFECTS IN PLAY.
WINDS STILL HAVE MORE OF A WSW FLAVOR TO THEM...PASTING SOME LIGHT
SNOW AND FLURRIES TO FAR NW LOWER...CENTERED AROUND EMMET/CHARLEVOIX
COUNTIES. THOSE LIGHT WINDS MAY ALLOW FOR THESE SNOW SHOWERS TO
SNEAK OUT OVER THE LAKE THOUGH...AND A MESOVORTEX IS POSSIBLE...BUT
MACKINAC COUNTY/STRAITS AND FAR NW LOWER ALL IN THE ZONE FOR
CONTINUED LIGHT SNOW/FLURRIES. MINIMAL ACCUMULATIONS...AS INVERSION
HEIGHTS DROP EVEN FURTHER WITH SOME MINOR WARM ADVECTION AT H8 TO
WHERE WE MAY NOT EVEN BE ABLE TO INTRODUCE ICE CRYSTALS. NOBODY OVER
AN INCH IS THE EXPECTATION.

HIGHS IN THE UPPER 20S AND LOWER 30S TODAY WITH LOWS TONIGHT IN THE
TEENS TO AS MILD AS THE LOW TO MID 20S IN LAKE EFFECT/CLOUDS.


&&

.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 401 PM EST MON NOV 24 2014

HIGH IMPACT WEATHER POTENTIAL: ACCUMULATING SNOW CONTINUES THROUGH
MIDDAY TUESDAY...WITH ADDITIONAL MAINLY LIGHT SNOW CHANCES TOWARD
WEDNESDAY NIGHT AND THURSDAY...POSSIBLY ENHANCED NEAR THE STRAITS.

PATTERN SYNOPSIS/EVOLUTION: NORTHERN STREAM TROUGH DOMINATION
RETURNS ACROSS THE GREAT LAKES/CENTRAL CONUS THROUGH MIDWEEK...
COURTESY OF REX BLOCK REDEVELOPMENT THROUGH THE GULF OF ALASKA AND
SUBSEQUENT RIDGE AMPLIFICATION ALONG THE WEST COAST OF NORTH
AMERICA. EMBEDDED WITHIN THE OVERALL MEAN UPPER TROUGH WILL BE
SEVERAL INDIVIDUAL SHORTWAVES...WITH THE FIRST LIFTING TOWARD
SOUTHERN LAKE MICHIGAN AT THE MOMENT - OUR FUN FOR TONIGHT/TUESDAY.
ADDITIONAL SHORTWAVE ENERGY IS EXPECTED TO DIVE FROM ALBERTA DOWN
THROUGH THE TENNESSEE VALLEY WITH A SEPARATE PIECE OF ENERGY ROLLING
THROUGH OUR NECK OF THE WOODS TOWARD WEDNESDAY NIGHT/THURSDAY. AS
WOULD BE EXPECTED...EACH SYSTEM WILL PROVIDE ITS OWN SET OF FORECAST
CHALLENGES...MAINLY OF THE "HOW MUCH SNOW" VARIETY.

TUESDAY: BY FAR THE PERIOD WITH THE MOST WIDESPREAD ACTIVE WEATHER.
SECONDARY UPPER TROUGH SLATED TO BRING A QUICK ROUND OF SNOW TO THE
AREA TONIGHT WILL LIFT TO OUR NORTHEAST...WITH ANOTHER WEAK WIGGLE
IN THE FLOW WORKING ACROSS THE REGION INTO EARLY AFTERNOON.
PREVALENT DEEP LAYER MOISTURE COMBINED WITH LINGERING MID LEVEL
DEFORMATION FORCING SHOULD YIELD A PERSISTENT THOUGH LESS INTENSE
AXIS OF SNOW WORKING ACROSS MUCH OF THE CWA. STARK LOW LEVEL
CYCLONIC CURVATURE THROUGH THE MORNING WORKING IN TANDEM WITH MODEST
LAKE INSTABILITY (DELTA T`S AROUND 18C) SHOULD ADD A BOOST TO THE
OVERALL LIGHT SNOW SHIELD FOR FAVORED NW TO W/NW FLOW AREAS. RATHER
DEEP AXIS OF DENDRITIC GROWTH POTENTIAL LOOKS TO BE UNDERCUT BY THE
BEST LAKE-INDUCED OMEGA...SUGGESTING RATIOS MAY NOT BE OVERLY
HIGH...THOUGH LIKELY STILL ON THE ORDER OF 15+ TO 1 SIMPLY GIVEN THE
DEEPER NATURE OF THE DGZ. ALL TOLD...EXPECT A GENERAL 1-1.5" OF
ADDITIONAL SYNOPTIC SNOW ACCUMULATION THROUGH THE DAY...PRIMARILY
DURING THE MORNING...WITH LOCALIZED HIGHER AMOUNTS PUSHING 2-4" FOR
THE FAVORED AREAS.

TUESDAY NIGHT-WEDNESDAY: DEEP MOISTURE WILL THIN QUICKLY BY TUESDAY
EVENING...WITH WEAKENING FLOW EXPECTED AS LOW LEVEL RIDGING ATTEMPTS
TO BRIDGE THE GREAT LAKES. THESE TYPES OF SETUPS ARE ALWAYS A
CHALLENGE FROM A LAKE SNOW STANDPOINT AS WEAK FLOW IN A STILL
UNSTABLE ENVIRONMENT TENDS TO PROMOTE PLENTY OF MESOSCALE
PROCESSES... AND INDEED WE MAY WELL SEE THIS TYPE OF SETUP PLAY OUT.
BACKED FLOW REGIME MORE W/SW SHOULD FAVOR PERSISTENT LIGHTER SNOW
SHOWERS UP TOWARD THE TIP OF THE MITT COUNTIES...WITH AT LEAST SOME
POTENTIAL FOR A MESOSCALE VORTEX OR TWO TO SPIN UP AS HINTED AT BY
SEVERAL PIECES OF GUIDANCE THE PAST FEW DAYS. OVERALL...DON`T
ANTICIPATE ANY SIGNIFICANT SNOW AMOUNTS...WITH PERHAPS EVEN SOME
SUNSHINE FOR INLAND AREAS ON WEDNESDAY.

WEDNESDAY NIGHT-THURSDAY: NEXT NORTHERN STREAM WAVE DROPS INTO THE
NORTHERN LAKES...FURTHER HELPING ENHANCE EXISTING LAKE-INDUCED
TROUGHING. INCREASE IN SYNOPTIC MOISTURE SHOULD WORK WITH WEAKER
SOUTHWEST FLOW TO DELIVER AN ENHANCED SNOW BAND SOMEWHERE UP TOWARD
THE TIP OF THE MITT COUNTIES (PLACEMENT VERY UNCERTAIN)...WITH A
NICE FLAREUP OF SNOW SHOWERS EXPECTED ALONG A COLD FRONT DROPPING
THROUGH THE CWA BY THURSDAY MORNING. HAVE SEEN THESE TYPES OF SETUPS
QUITE A FEW TIMES OVER THE YEARS...AND TYPICALLY THERE IS A QUICK
BURST OF 1-2" OF SNOW THAT ACCOMPANIES THE BOUNDARY...PARTICULARLY
JUST DOWNWIND OF LAKES SUPERIOR AND MICHIGAN. SEE NO REASON THAT
COULDN`T HAPPEN HERE...WITH A QUICK TRANSITION OVER TO NW OR N/NW
FLOW LAKE SNOW SHOWERS ANTICIPATED FOR THE DAY ON THURSDAY AS A
CHUNK OF QUITE CHILLY AIR (H8 TEMPS AROUND -18C) PLUNGES INTO
NORTHERN MICHIGAN.

EXTENDED PERIODS (THURSDAY NIGHT THROUGH SUNDAY)...

WEAK SHORT WAVE CONTINUES TO PUSH EAST OF THE AREA THURSDAY NIGHT
WITH THE MAJORITY OF ANY LINGERING LAKE EFFECT ENDING BY 12Z FRIDAY
AS 1000-850 MB WINDS SHIFT FROM NORTH-NORTHWEST TO SOUTH-SOUTHWEST.
SLIGHT DIFFERENCES BETWEEN TIMING OF NEXT DISTURBANCE APPROACHING
FRIDAY AFTERNOON...BUT EITHER WAY LOOKS LIKE A DECENT SHOT OF WARM
ADVECTION/OVERRUNNING SNOW FRIDAY AFTERNOON INTO FRIDAY NIGHT.

STRONG WARM AIR ADVECTION CONTINUES SATURDAY AS SURFACE LOW PASSES
NORTH THROUGH ONTARIO WHICH MAY LEAD TO TEMPERATURES ONCE AGAIN
RISING ABOVE FREEZING...BUT WON`T LAST LONG AS THE LOW CONTINUES
INTO QUEBEC AND SWINGS A COLD FRONT THROUGH NORTHERN MICHIGAN DURING
THE LATE SATURDAY NIGHT/SUNDAY TIMEFRAME. COLD TEMPERATURES ALONG
WITH HIGH PRESSURE IS EXPECTED TO BUILD IN TO START THE NEXT WORK
WEEK...BRINGING WHAT LOOKS TO BE AT LEAST A SHORT STRETCH OF QUIET
WEATHER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1145 PM EST MON NOV 24 2014

WIDESPREAD SNOW AND IFR CONDITIONS WILL CONTINUE OVERNIGHT AND THRU
MUCH OF TUESDAY AS THE DEFORMATION AXIS AND DEEP WRAP-AROUND
MOISTURE ON THE BACKSIDE OF THE DEPARTING SURFACE LOW REMAIN
OVERHEAD. INCREASING OVER-LAKE INSTABILITY WILL LEAD TO SOME W/NW
FLOW LAKE CONTRIBUTION TO SNOWFALL INTENSITY FOR THE TYPICAL
SNOWBELT REGIONS OF NW AND N CENTRAL LWR MICHIGAN.


&&

.MARINE...
ISSUED AT 219 AM EST TUE NOV 25 2014

GALES HAVE ENDED ACROSS THE LAKE HURON NEARSHORE WATERS AND HAVE
CANCELLED THE WARNING. STILL GONNA GET SOME ADVISORY LEVEL GUSTS
THROUGH TODAY...AS WELL AS PERIODICALLY ACROSS MOST ALL OTHER
NEARSHORE WATERS. WILL HAVE AN ADVISORY UP EVERYWHERE TODAY.
WINDS DO WEAKEN HEADING THROUGH THE DAY AND ESPECIALLY INTO
TONIGHT.

THEN...A LIGHT...AND AT TIMES VARIABLE WIND...IS ANTICIPATED
THROUGH WEDNESDAY EVENING. A STRONG COLD FRONT ARRIVES FROM THE
NORTH AND WILL LIKELY RESULT IN ADVISORIES FOR MOST NEARSHORES
INTO THURSDAY EVENING.

&&

.HYDROLOGY...

RECENT SNOWMELT HAS RESULTED IN CONTINUED RISES IN MANY RIVERS AND
STREAMS ACROSS NORTHERN MICHIGAN. WHILE THERE ARE NO SIGNIFICANT
FLOODING ISSUES...THE MANISTEE RIVER AT SHERMAN IS EXPECTED TO REACH
A MINOR FLOOD STAGE THIS MORNING...AS WELL AS THE RIFLE RIVER NEAR
STERLING THIS EVENING.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ008-
     015>023-025>029-031>034.

     WINTER WEATHER ADVISORY FROM 4 PM TO 5 PM EST THIS AFTERNOON FOR
     MIZ024-030-035-036-041-042.

LH...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     LHZ345>349.

LM...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LMZ323-
     341-342-344>346.

LS...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LSZ321-
     322.

&&

$$

SYNOPSIS...MJG
SHORT TERM...SMD
LONG TERM...LAWRENCE/MJG
AVIATION...MLR
MARINE...SMD
HYDROLOGY...SMD


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